Electromagnetic switch.



E. R. CARICHOPF. ELECTROMAGNETIC SWITCH. APPLICATION FILED SEPT.11,1912.

1,084,396. Patented Jan. 13, 1 914.

29 Fig. l.

\Nitmesses lm/entor Eugene F.Car-ich0ff I/ I} f 4 by W@% Misfittornes UNITED i OFFIE.

EUGENE R. GARICHOFF, OF SCHENECTADY, YORK, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTROMAGNETIC SWITCH.

Specification of Letters Patent .Patented Jan. 13, 191%.

Application filed September 11, 1912. Serial No. 719,713.

' Schenectad in the county of Schenectady,

, State of ew York, have invented certain new-and useful Improvements in Electromagnetic Switches, of which the following is a specification.

Thls invention relates to devices for controlling electric circuits, and has for its object the provision of a device of this character whereby an electric circuit may be automatically opened and closed in a reliable, safe and ellicient manner.

My invention relates more specifically to electromagnetic switches for opening and closing an electric circuit from a remote point. One of the common uses of a switch of this character is for controlling the circuit of an electric motor. These switches, as ordinarily constructed, consist of a switch member that is moved to closed position by an actuating winding, generally a shunt winding, and when the winding is denerzed the switch member drops open by gravity. Some times the switch member is held in open position by a spring so that it will open by a positive action. In some cases, it is desirable that the switch shall open with a quick action, although a spring for opening it would be objectionable. If the spring were still enough to effectively open the switch, it would be too still to permit the closing of the switch by the actuating Winding. It is particularly desirable that the switch shall open with a quick action upon the occurrence of an overload on the line, since in this case the current to be broken is relatively heavy.

In carrying out my invention, I provide means whereby the electromagnetic switch is magnetically opened as well as magnetically closed. In the case of opening the switch on overload, the arrangement is such that the overload winding actually pulls the switch open. In one specific embodiment of my invention when an overload occurs the overload coil first causes the circuit of the actuating winding to be opened and then acts upon the switch member to pull it open. In order that the switch shall not close again without the attention of the operator, I provide means for positivel holding the circuit of the actuating win ing open until the nnerator by performing some operation, as

4 member 18 whichis for instance, by actuating a separate switch .which shall allow the energizing circuit to be closed.

In the accompanying drawing in which I have illustrated my invention embodied in a concrete form for purposes of illustration, Figure 1 represents the structural arrange ment of one embodiment of my invention,

and Fig. 2 is a diagrammatic representation of the same, showing the circuit connections for controllin a motor circuit.

Referring rst to F ig. :2, it will be seen that I have shown my switch for controlling the circuit of an electric motor having an armature A, and a series field F. The switch member consists or a switch arm 10 pivoted at 11, so as to cooperate with a stationa'ry contact 12 to open and close the motor circuit. This switch member is moved to closed position by an actuating winding 13, which in this case is a shunt winding. The winding 13 is in the form of .a solenoid having a movable core 14, to the lower end of which. the switch arm 10 is piv oted' at 15. Upon energization of the wind ing 13, the switch mbmber 10 will be moved to closed position in engagement with the stationary contact 12. lnorder to move the switch member 10 to openfgiosition in a positive manner, I have provided another winding 16 which is also in the form of a solenoid, having a cooperating core 17. This core is likewise connected with the switch arm 10, so as to pull it downwardly when the winding 16 is energized. In the particular arrangement shown, the two cores 14 and 16 are connected together so as to form in effect one moving element, and the switch arm is connected to the central point 15. One terminal of the winding 16 is connected with the pivotal point 11 of the switch arm, and will, therefore, be in series with the motor armature when the switch arm is in closed position. This connection of winding 16 to pivotal point 11 is shown in Fig. 2, but is not shown in Fig. 1. Located below the core 17 so as to cooperate therewith is a ivoted at 19. This member has on its underside a spring contact 20, cobpcrating with a stationary contact 21, so as to constitute a switch for controlling the circuit of the actuating winding 13, one terminal of which is connected with the pivotal point 19. If the winding 16 is sufliciently energized the member 18 will be moved on its pivot and thereby open the circuit of the winding13 at the contacts 20 and 21. The movement of the member 18 toward the core 17 is limited by a stop 22 so that it can only move far enough to open the circuit of the winding13 but still be separated from the core 17 by an air gap. WVhen the member 18 is in the magnetic circuit of will, of course, be held stationary, and since the member 18 moves against the stop 22, it the core 17. there will be a magnetic pull between the core 17 and the member 18. The

member 18 being now stationary, it will cause the core 17 to be drawn downwardly and open the motor circuit.

In order to prevent the member 18 from droppingiback and again closing thecircuit of the winding 13 upon the deenergization of the winding 16, which of course will occur when the motor circuit is open, I provide a latch 23, pivoted at 24 for holding the member 18 in its raised position. The latch 23 is spring pressed to locking position by a spring 25. In order to trip the latch, and release the member, I have provided an electromagnet 26 which is under the control of the operator. For purposes of illustration I have shown the magnet 26 controlled by a separate switch 27 which may be located at any convenient point. The winding 13, as well as the motor circuit, is controlled by a controller C which may be of any well known design. I have shown a controller of the type in which the resistance sections R are cut out of circuit by the manual operation of the controller. One terminal of the winding 13 is connected with the contact 28 on the controller, so that the winding will be energized when the controller is moved to the first position. When the controller is moved to the second position, the motor circuit is closed through the resistance R, and in the succeeding positions, the sections of resistance will be cut out ofcircuit in a well understood manner.

In Fig. 1 I have shown a structural ar-,

rangement of one form of my switch. Since my invention does not in any sense relate to the structural details of this switch, I shall not attempt to describe the details of construction thereof, except those that relate to the features of my invention above referred to. Referring to this figure, it will be seen that the winding 13 is mounted in a frame 29 of magnetic material. The core 14 shown in dotted lines has pivoted at its lower end 15 the switch arm 10 which cooperates with the stationary contact 12 located in the arc chute 30. The core 17 of the series winding 16 is likewise connected with the switch arm 10 as shown. The member 18 pivoted at 19 is moved dowm wardly into position shown in the-drawing by a spring 31, one end of which is secured to the frame at 32, while the other end is secured to a projection 33 on the movable member, the downward'movement of the member being limited by a lug 34 which abuts against the frame. The upward movement of the member is limited by the engagement of the projection 33 with the beveled surface 22 corresponding to the stop in Fig. 2. The contact 20 is secured to the underside of the member 18, as before described, and cooperates with the stationary contact 21. The latch 23 is pivoted to the frame 24, so that it will engage the member 18 and hold it in raised position. The magnet 26 is mounted in the frame adjacent to the latch, so as to cotiperate therewith to release the member, as before described.

The arrangement of the circuits and mode of operation of my device are as follows When the controller C is moved to the first position, the winding 13 will be energized so as to move the switch member 10 to closed position. \Vhen the controller is moved to the second position the motor circuit is closed from the positive side of the line through the resistances R, the overload coil 16, switch arm 10, armature A and field F to the opposite side of the line. By further ,movement of the controller, the resistances R will be cut out of circuit and the motor brought to running speed. If now an overload should occur, the winding 16 will become sufiiciently energized to move the member 18 against the stop 22, thereby opening the circuit of the winding 13 at the contacts 20 and 2].. As soon as the winding 13 is deenergized, the core 17 will be pulled downwardly so as to open the switch with a quick positive movement. \Vhen the member 18 is raised to open the circuit of the winding 13 it is latched in the raised position so that, upon the deenergization of the winding 16 it will not again close. To again effect the closing of the switch, the operator must close the switch 27 which will energize the winding 26 and trip the latch, to permit the member 18 to drop and close the contacts 20 and '21. The controller shou d be in the off position when this is done, as is well understood in the art and the circuit connectionsmay be such as to make this sequence of operation necessary. However, I have simply shown the switch 27 as an auxiliary switch convenient to the operator,

and may be arranged in any desired manner. After the contacts 20 and 21 are closed, the motor can, of course, be started as before.

l Vhile I have described my invention as embodied in concrete form and as operating in a specific manner in accordance with the patent statutes, it should be understood that I do not limit my invention thereto, since various modifications of my invention will occur to those skilled in the artwithout,dc' parting from the spirit of my invention, the

scope of which is set forth in the annexed claims. I

What I claim as new and desire to secure by Letters Patent of the United States, 1s

1. An electromagnetic switch comprising a switch member, an actuating winding for moving the same to closed position, and an overload coil arranged to open the circuit of said actuating winding and then move the switch member to open position.

2. An electromagnetic switch comprising a switch member, an actuating winding for moving the same to closed position, and an overload device arranged to open the circuit of the actuating winding and thereafter exart a magnetic pull upon the switch member to cause it to open quickly.

3. An electromagnetic switch comprising a switch member, a shunt windingfor closing the same, a winding in series with the switch member for opening the same, anda switch in. the circuit of a shunt coil controlled by the series coil.

4. An electromagnetic switch comprising a switch member, an actuatin winding for closing the same, a winding 1n series with the switch member, and means controlled thereby for first opening the circuit of the actuating winding and then moving the swltch member to open position.

. 5. An electromagnetic switch comprising a switch member, a shunt winding for closmg the same, a series winding, and means whereby a predetermmed current flow in said winding causes it to first open the circuit of the shunt winding and then move the switch. member to open position.

6. An electromagnetic switch comprising a switch member, an actuating winding for moving the same to closed position, an overload coil for moving the member to open position, a switch controlled by .said overload coil for deenergizing the actuating winding, and electromagnetically controlled means for holding said switch in a deenergizing position.

7. An electromagnetic switch comprising a switch member, a winding for moving it to one position, a second winding for moving it to the opposite position when said first winding is denergized, a switch in the circuit of said first winding controlled by the second Winding, and a latch for holding said switch in open position.

8. An electromagnetic switch comprising a switch member, a winding for moving it v to one position, a second winding for moving it to the opposite position when said first winding is deenergized, and a switch in the circuit of said first winding controlled by the second winding.

9. An electromagnetic switch comprising a switch member, an actuating winding for closing the same, a series winding havm a movable core operatively connected with said member for opening the same, a movable member included in the magnetic circuit of said core arranged to deenergize the closing the same, a series winding having a movable core operatively connected to said member for opening the same, a movable member included in the magnetic circuit 01 said core to deenergize the actuating winding upon the predetermined current flow in the series Winding and thereafter magnetically attract the core so as to move the switch member to open position, and electro magnetically controlled means for holding said movable member in open position.

11. An electromagnetic switch comprising a switch member, an actuating Winding for closing the same, a series winding having a movable core operatively connected to said member for opening the same, a movable member included in the magnetic circuit of said core for deenergizing the actuating winding upon a predetermined current flow in the series winding, and thereafter magnetically attracting the core so as to move the switch member to open position, a latch for holding said movable member in open posit-ion, and an electromagnet controlling said latch to release said movable member. In witness whereof, I have hereunto set my hand this 9th day of September, 1912.

EUGENE R. OARICHOFF. Witnesses:

BENJAMIN B. HULL, HELEN Onronn.

It is hereby certified that in Letters Patent No. 1,084,396, granted J n y 1914, upon the up iliqeltion of Eugene H. Cerichofl', of Schenectady, N York, for

an improvement in Electromagnetic Switches, errors appear in the printed specification requiring correction as follows: Page 2, strike out lines 8-10, and insert the words the member 18 m agaimt t/w m 293, it will, of emu-8e, 6 W 8t'afii0flar'y, qntlhince t/w'member 18 is in the mdgnetic circuit 0 same pflg i line l the wor resistanee read remlstdnces; and that the said Letters Patent sho l be read with .these corrections therein that the same may conform to t regar f the case in the Patent Oflicei Signed and :sealed this 3rd day of February, A. D., 191 4. mt-i J. r. NEWTON,

A (tiny Commieaioner of PM. 

